To the present writing, lymphocytes from 6 normal persons, and 19 samples from 9 patients with chronic lymphocytic leukemia have been studied. The procedures used involve the separation of lymphocytes on glass-bead columns and the removal of erythrocytes by treatment with isotonic ammonium chloride. The histone synthesis is studied in 3 types of cell preparations, whole cells, nuclei, and microsomes. They are studied both before and after culturing the cells in Medium-199 in the presence and absence of PHA-MA with radioactive lysine and arginine added in the last hour of incubation. The isolated histone fractions are separated on acrylamide gels, and the radioactivity of the slices determined by scintillation counting. The histones from nuclei from whole cell incubation or from synthesis with nuclei gave similar results. Four main fractions were in evidence: F1, F2b, F2a2, and F2a1. The F3 band was present if a sufficiently large sample was used, and was present as 3 bands if mercaptoethanol was added to prevent aggregation. Additional bands were often found between F2a2 and F2a1 and pre-F2b. Quantitative differences may be noted. In the assay of histone on microsomes, many bands were noted on eledtrophoresis, most of them migrating distal to the F3 band. That they are basic proteins is evidenced by their not migration in the conventional electrophoresis at pH 8.6.